Kei Nishikori has admitted that he felt "a little bit nervous" at the start of his match against Steve Johnson in the third round of the Australian Open this morning.

The fifth seed had to come from a set down to book his place in the fourth round at the expense of the American.

The Japanese player told reporters: "It was a nice battle and I was playing solid in the last couple of sets, so it was a very good win today.

"I was a little bit nervous early but I started to get the rhythm and started to play solid, so I am very happy to go through.

"I think from now on it will be a tougher opponent coming up, but I've won three good matches so it was exciting to play here today."

Nishikori will face the winner of the match between David Ferrer and Gilles Simon in the next round.